In members constituting electric and electronic devices such as a copy machine and a printer, various materials are used in consideration of characteristics and functions required for the members. For example, for a member (case) that plays a role of receiving a driving apparatus of an electric and electronic device or the like, and protecting the driving apparatus, a large amount of PC (polycarbonate), an ABS (acrylonitrile-butadiene-styrene) resin, PC/ABS or the like are generally used (Patent Document 1). These resins are prepared by reacting compounds obtained by using petroleum as a raw material.
By the way, fossil resources, such as petroleum, coal and natural gas, include carbon fixed under the earth over a long period of time as a main component. In the case where carbon dioxide is discharged into the atmosphere by combusting such fossil resources or products using the fossil resources as a raw material, carbon that does not exist in the atmosphere but is fixed deeply under the earth, is rapidly discharged as carbon dioxide, and thus, carbon dioxide in the atmosphere is largely increased, thereby causing a global warming. Accordingly, a polymer such as ABS and PC having petroleum, which is a fossil resource, as a raw material has excellent properties as a material of the member for electric and electronic devices, but since petroleum, which is a fossil resource, is used as the raw material, it is preferable that the amount used is decreased from the standpoint of preventing the global warming.
Meanwhile, a plant-derived resin is basically generated by a photosynthesis reaction using water and carbon dioxide in the atmosphere as raw materials by plants. Therefore, there is an opinion that, although carbon dioxide is generated by combusting a plant-derived resin, the carbon dioxide corresponds to carbon dioxide previously existing in the atmosphere, and thus, the balance of carbon dioxide in the atmosphere becomes zero-sum, such that the total amount of CO2 in the atmosphere is not increased. Based on this opinion, the plant-derived resin is called a “carbon neutral” material. The use of the carbon neutral material instead of the petroleum-derived resin has gained importance in preventing the current global warming.
Therefore, in the PC polymer, there is proposed a method for decreasing petroleum-derived resources by using plant-derived resources such as starch as a portion of the petroleum-derived raw materials (Patent Document 2).
However, there is a need for further improvement from the standpoint of targeting a more perfect carbon neutral material.
As a known cellulose derivative, hydroxypropylmethylacetyl cellulose is described in Patent Documents 3 and 4. Patent Documents 3 and 4 describe that the hydroxypropylmethylacetyl cellulose is useful as an additive for reducing the vapor pressure of organic solvents which are easily volatilized. Further, for the degree of substitution of each substituent in the hydroxypropylmethylacetyl cellulose described in Patent Documents 3 and 4, for example, it is described that a molar degree of substitution (MS) of a hydroxypropyl group is in a range of about 2 to about 8, a degree of substitution of a methyl group is in a range of about 0.1 to about 1, and a degree of substitution of an acetyl group is in a range of about 0.8 to about 2.5.
Moreover, as a use of coating of medicaments, hydroxypropylmethylpropyl cellulose, hydroxypropylmethylbutyl cellulose, and the like (Patent Document 5), and hydroxypropyl methylcellulose phthalate, and the like, (Patent Document 6) are disclosed.